A variety of designs have been commercialized or proposed for instruments incorporating a pair of cooperating jaws (i.e., a jaw assembly) in which one jaw pivots or otherwise moves relative to the other jaw between open and closed positions. Examples of such instruments include tissue graspers, tissue clamps, needle graspers, tissue cutters, linear staplers, ligating clip appliers, and the like.
In many surgical procedures, the working area is confined, and instruments with relatively small cross sections are necessary or preferred. Thus, it would be desirable to provide an improved jaw assembly that can be incorporated in a surgical instrument and that has a relatively small cross section.
Some instrument designs have been developed for linear stapler systems wherein one jaw functions as an anvil and the other jaw carries a row or rows of staples. The anvil jaw can be closed manually to trap layers of tissue between the two jaws. Then, a suitable mechanism is actuated to discharge the staples through the tissue and against the anvil jaw. It would be beneficial to provide an improved jaw assembly design that could readily accommodate a staple application system and permit opening and closing of the jaws remotely from the proximal end of the instrument.
When pivotally-mounted jaws are employed to clamp or squeeze tissue, the proximal portions of the jaws typically engage the tissue before the distal portions of the jaws engage the tissue. This can cause the tissue to be forced distally in the jaws, and the tissue may then not be properly engaged by the jaws. It would be desirable to provide an improved jaw assembly that could close the jaws in a way that would eliminate or minimize the tendency of the tissue to move along the jaws as the jaws close.
In some surgical applications, it is necessary or advantageous to apply relatively high squeezing forces. Thus, it would be desirable to provide an improved jaw assembly that can provide a mechanical advantage for increasing the jaw closure force compared to the operator input force. It would also be beneficial if the jaw assembly could accommodate designs wherein the closure force at the jaw assembly can be varied during the closure stroke.
Additionally it would be advantageous to provide an improved jaw assembly that could be incorporated in instruments used in endoscopic surgical procedures as well as in instruments used in open surgery procedures. As used herein, the term "endoscopic" pertains generally to the use of a surgical instrument which is inserted into a body cavity in conjunction with an endoscope that is inserted into the same body cavity. The endoscope permits visual inspection, with or without magnification, of the interior of the body cavity and permits observation of the operation of the surgical instrument for therapeutic or diagnostic purposes.
In a typical endoscopic surgical procedure, the abdominal cavity of a human or animal subject is insufflated with a sterile gas, such as carbon dioxide, in order to provide increased maneuvering room within the body cavity for endoscopic instruments. Then, conventional trocars are inserted into the subject's body cavity through the surrounding skin, tissue, and musculature. A conventional trocar typically consists of a trocar cannula which houses an elongated trocar obturator. Trocar obturators typically have a piercing point, although other types of obturators are also available.
After each trocar has been positioned within the body cavity adjacent the target surgical site, the trocar obturator is removed leaving the trocar cannula as a pathway to the body cavity. A plurality of trocar cannulas are typically placed in this manner. The surgeon can then insert an endoscope through one of the trocar cannulas and can insert various types of endoscopic, surgical instruments through one or more of the other trocar cannulas at the target surgical site where the diagnostic or therapeutic surgical procedure is performed.
The endoscope is typically connected to a video camera, and the output from the video camera is fed to a video monitor which displays the surgical site and the end of the endoscopic instrument at the surgical site. Some endoscopic instruments incorporate a pair of jaws (e.g., ligating clip appliers, tissue cutters, tissue graspers, needle graspers, and the like). Thus, it would be desirable to provide an improved jaw assembly that can be employed in such endoscopic instruments and that can easily accommodate operation and control from the proximal end of the instrument exterior of the body cavity.
Although endoscopic surgical procedures offer many advantages, there are some problems associated with these procedures as conventionally practiced. For example, because the surgeon typically views the display on the video monitor as he manipulates instruments within the body cavity, the video display provides the surgeon with only a two-dimensional view of the surgical site, and there is a consequent loss of depth perception.
Another problem relates to engaging tissue from the instrument insertion direction. Some conventional, endoscopic instruments (e.g., graspers) include a jaw assembly for engaging the tissue in a way that effects the desired result (e.g., squeezing the tissue). In some of these conventional, endoscopic instruments, the jaws are mounted to, and extend generally linearly with, a rigid, straight shaft of the instrument.
Depending upon the nature of the operation to be performed on the tissue within the body cavity, it may be desirable to provide a jaw assembly which can be angled or articulated relative to the longitudinal axis of the instrument shaft. This can permit the surgeon to more easily engage the tissue in some situations.
A further problem relates to the potential for blocking part of the field of view with the endoscopic instrument. Thus, the use of an endoscopic instrument with an articulating distal end would permit the surgeon to engage the tissue with the jaws laterally offset relative to the instrument's main shaft. This would permit the engaged tissue and jaws to be better viewed through an adjacent endoscope with little or no interference from the main shaft.
Although a number of designs have been proposed for articulating endoscopic instruments, and although articulating endoscopes and other instruments are commercially available, it would be desirable to provide an improved design for a remotely operated jaw assembly that can accommodate articulation of the distal portion of the instrument to which the jaw assembly is mounted.
In particular, it would be advantageous to provide a jaw assembly for an articulating instrument (endoscopic or non-endoscopic) with the capability for jaw operation even when the assembly is oriented at a substantial oblique angle relative to the longitudinal axis of the instrument. Further, it would be beneficial if such an improved design permitted operation of the jaw assembly while the jaw assembly is articulated in any radial direction around the longitudinal axis of the instrument.
In endoscopic surgery it may be desirable in some situations to sense environmental characteristics at the surgical site (e.g., temperature, chemical, etc.). Further, it may be desirable to sense the actual presence or position of a component of the instrument. In addition, it may be beneficial to provide conduits for irrigation or aspiration at the surgical site. It may also be necessary to provide clips or staples at the site and to provide means, carried in the jaw assembly, for applying the clips or staples. Accordingly, it would be especially advantageous to provide an improved jaw assembly which can accommodate internal sensor lines, aspiration conduits, irrigation conduits, and flexible actuator members, and which can also accommodate the feeding and application of fasteners (e.g., of clips and staples). Such an improved jaw assembly should preferably have sufficient interior space that can accommodate internal passages and components and that can permit the movement of such components through the jaw assembly.
It would also be advantageous if such an improved jaw assembly for an endoscopic or open surgery instrument could be provided with a relatively smooth exterior configuration having a minimum of indentations and projections that might serve as sites for contaminants and be hard to clean or that might be more likely to catch on, or tear, adjacent tissue.
It would also be beneficial if such an improved jaw assembly could be provided with sufficient strength to accommodate relatively high moments and forces during operation of the instrument jaw assembly in an articulated orientation as well as in a straight orientation.
The present invention provides an improved jaw assembly for an instrument used in a surgical procedure which can accommodate designs having the above-discussed benefits and features.